1. Field of the Invention
The present invention relates to a mold element having a plurality of metallic elements secured to each other by means of a bonding agent, and a related method.
2. Brief Description of the Prior Art
It is well known to provide molds for casting certain objects. These molds have a cavity which is formed therein to correspond substantially to the external shape of the casting to be cast. The cavity is adapted to be filled with casting material through a suitable pouring hole.
Many times there is a need to form internal passages in metal castings. In order to accomplish this a "core" or "cores" are placed in the mold. Mold cores are traditionally produced from loose, divided grains which are "bound" or "adhered" together in a manner such that a solid structure is fashioned. These materials afford dimensional and structural stability and resist the tendency to combust. See U.S. Pat. Nos. 3,008,200 and 3,228,074. Once the molten metal is poured around such a core structure and the metal again solidifies, the core must be removed in such a fashion that the internal passage is retained within the cast shape. The most wide-spread method of core removal is disintegration of the core by "knock-out" methods using vibration and/or shock and by impact blast cleaning through the use of a focused media stream.
Traditionally, mold and mold core materials have consisted of various silica grains, ceramic grains, clays, and the like, held in place by "binders" of numerous compositions, such as a phenolic resin. See U.S. Pat. No. 3,228,074. It has also been known to magnetize the core material See U.S. Pat. No. 3,008,200.
Use of metal-metal oxide compositions for various articles is known. See, for example, U.S. Pat. No. 4,255,193 and United Kingdom Patent No. 321,394.
There is a present demand for greater casting integrity and for improved casting density in thin cast sections. There remains therefore, a very real and substantial need for inexpensive molds and mold cores that may be provided in a range of sizes that retains a high degree of structural accuracy.